2008 Year in Review

From the Fields

“What’s that gallon milk jug wired to the post all about?” A farmer asked me that question recently as I was checking the plastic container, which also serves as a western bean cutworm pheromone trap.

Monitoring for the western bean cutworm moth, using plastic milk jugs and a specific lure, began in late-June and will continue till mid-August. Results from the monitoring effort across the Midwest are reported on Iowa State University’s Western Bean Cutworm Monitoring Network.

Historically, the western bean cutworm has been a pest in the western cornbelt but over the last few years it has moved east across Iowa. The pest was first detected in Illinois in 2004 in Warren County. The larva of the insect feeds on both corn and dry beans, affecting both yield and quality of the crop. Unlike cutworms, the western bean cutworm is a late-season pest of corn feeding mainly on the ears, predisposing them to disease infections.

In corn, the female moth lays their eggs on the upper surfaces of leaves. After hatching, the larvae pass through five instars and feed on host plants for about 30 days.

Newly hatched larvae move from the leaves to the corn whorls to feed on the tassels and then to the silks. As the larvae and corn ears develop, the larvae begin feeding on ear tips. An ear may be infested by more than one larva, and this feeding can cause economic damage.

In Illinois, the western bean cutworm has been more commonly found in northwestern and north-central counties. More information will be shared as the growing season progresses. A fact sheet on the western bean cutworm can be found at this University of Illinois web site at IPM.

by  Editor, theCity1.com
July 14, 2008